Simultaneously harvesting mechanical and chemical energies by a hybrid cell for self-powered biosensors and personal electronics

Electrochemical cells (ECs) are devices that convert chemical energy into electricity through spontaneous oxidation–reduction reactions that occur separately at two electrodes through the transport of protons in the electrolyte solution and the flow of electrons in the external circuit. A triboelectric nanogenerator (TENG) is an effective device that converts mechanical energy into electricity using organic/polymer materials by a contact induced electrification process followed by charge separation. In this paper, we demonstrate the first integration of an EC and a TENG for simultaneously harvesting chemical and mechanical energy, and its application for powering a sensor and even personal electronics. An EC was fabricated using a Cu/NaCl solution/Al structure, on which a thin polydimethylsiloxane (PDMS) film with a micropyramid surface structure was used as the protection layer of the EC for anti-corrosion, anti-contamination and anti-mechanical damage. A TENG was fabricated based on a contact-and-separation process between the PDMS protection layer and the Al electrode layer of the EC. The output performance of the TENG can be increased by embedding BaTiO3 nanoparticles into the PDMS film layer to enhance the dielectric property. Moreover, we also demonstrated that the produced hybrid energies can be stored in a Li-ion battery for lighting up 30 green LEDs.